Feature Request: Add extensibility point to override object value

[randyburden]

Feature Request: I would like the ability to modify any object's value. For instance, I've got an object that has an Image property that is holding an image as a base64 encoded string. I would like to turn this value into this:

<img src="data:image/jpg;base64,/9j/4AAQSkZJRgABAQEAYAB..." />

In order to do that, we would need a config option that allows you to specify a function that the library will call to return the innerHtml of each cell. This function of course would need to have some context passed into it so that you could interrogate the particular object and key value pair being evaluated.